Spanish patent ES 2084801T (equivalent to European patent EP 443983) discloses acyl compounds, among them the Valsartan of formula (I):

Said Spanish patent discloses how it is prepared by converting a phenyl substituent (Z1) into tetrazole, where Z1 is a group convertible into tetrazole, and can among others be a halogen group. The examples of said patent describe the specific case in which Z1 is a cyano group or a protected tetrazole ring. This is followed by final deprotection of the carboxylic acid group, where R is preferably methyl or benzyl and, where applicable, of the tetrazole ring protective group, preferably a trityl group.

That patent, leaves room for improvement of aspects such as the utilisation of azide in the last synthesis steps, with the attendant risk of explosion if sodium azide is used or environmental problems if tributyl tin azide is used.
Another negative aspect lies in the use of large protective groups for both the tetrazole ring (trityl group) and for the carboxylic acid of the valine moiety (benzyl group), which increase very considerably the molecular weight, of the last synthesis intermediate, which is dramatically reduced subsequently in the final hydrolysis to yield Valsartan, resulting in a process of low atomic efficiency. This further creates a considerable amount of residual products and increases the number of synthesis steps in the process.
Patents DE4313747, DE4407488, U.S. Pat. No. 5,596,006, EP594022 and WO9609301 describe the synthesis of sartans by means of formation of the biphenyl system by reacting an aryl halide with the 2-(1H-tetrazol-5-yl) phenylboronic acid in the presence of a palladium catalyst.
A safe, ecological and high-yield process for obtaining Valsartan with few synthesis steps and using simple and commercially available starting products therefore remains necessary. Additionally, it must be possible to apply said process on an industrial scale and avoiding racemisation and the consequent separation of enantiomers.